Pulled the cam out for a couple reasons, keep it or replace?

[Paul G]

Had a couple reasons to pull the cam from the 68 383 thats in the 73 Charger I recently dragged home.

1. The car has a chicken shit electric fuel pump because the fuel pump push rod was mushroomed out at the cam end of the rod and would not slide out. With the cam out I filed down the rod and slid it out. Now I can get a new push rod and a reliable mechanical fuel pump.
2. The timing is whacky, all over the place. I could actually feel slop in the timing chain when rotating the crank back and forth by hand. Had the base timing up to 25* to get it to run half way decent. But still not right. The chain is stretched half a tooth. Needs a new chain and gears.

I took a pic of the chain and gears, and the cam numbers.




The fuel pump lobe on the cam was chewed up a little. I sanded it smooth with 150 grit up to a polish with 1000 grit. It might have been sent that way from Crane by the way it ate the push rod. Should I reuse it?

So now I need to decie if this cam should go back in, or replace it with something more modern? Lifters and cam lobes are fine. Crane numbers on the cam are HMV-278-2-NC. I didnt come up with much doing a Google search other than it is a common Chevy grind. 

I have a good cam in my stash. Came out of a 73 440 some years ago. Comp  XE256H-10 part 21-221-4
Duration @ .050" Lift: intake 212, exhaust 218
Intake Centerline: 106°
Valve Lift:   intake .447 exhaust .455

Some specs on the engine, has good vacuum, nice steady needle around 16", 68 383, 346 heads, long tube headers, proform 750 on stock spread bore intake with carb adapter, 323 gears, 4speed manual trans. 

[BSB67]

278°/290° Advertised
222°/234° @ 0.050"
114° lsa
0.467"/0.494" lift

Personally, I like the cam.  You could probably get a better cam, but that is pretty good in my book and if on a budget, I'd feel good about using it.

[Nacho-RT74]

with that cam I even would install a 1.6 ratio rockers and done

[c00nhunterjoe]

Youve come this far..... pull a head and see what pistons are in it, then decide from there.

[Challenger340]

278°/290° Advertised
222°/234° @ 0.050"
114° lsa
0.467"/0.494" lift

Personally, I like the cam.  You could probably get a better cam, but that is pretty good in my book and if on a budget, I'd feel good about using it.

I agree, I like the grind.
We used it "back in the day" many times, ran well with good power for one up resto stuff in those days.

[flyinlow]

lobe separation angle

[BSB67]

yes

[Paul G]

OK then, the Crane cam goes back in.

This low deck intake is available in town right now, he's asking $200. Eddy DP4B. Is it worth the effort to swap out the stock 1972 spread bore intake 3614046-1, for the Eddy DP4B? I wont need the carb adapter anymore.

[BSB67]

Without knowing more about the details of the motor, it's a guess. My observation is that in the world of second hand "warmed up 383s" or "mild HP improvements" can mean anything from a 250 HP to 350 HP motor.

If you are on the low end (they usually are) a factory spreadbore with a spreadbore carb can be a very good choice in my opinion.  I've used both TQ and Holley spreadbore carbs and liked them.  People say that the Street Demon is better yet.  If you are on the high end of that power range, the DP4B could add some power.

I tend to be a pessimist on the "should be" power claims, so maybe the factory intake would be better.   But I am also very opposed to adapters.  So I would prioritize getting a spreadbore carb on the factory intake, or putting a square flange intake under you carb.

That said, I don't think the DP4B would hurt you.  I am actually a fan of that intake.  If you go that route, be prepared to run paper gaskets on both sides of the pan gasket per side.  

[BSB67]

Also, FWIW, I've never found a stretched chain to solve a poor running motor condition.  It always ends up being something else.  And of course the need for 25° initial has nothing to do with the chain.  Spark scatter, maybe, but unlikely enough to make a noticable difference on a driver.

[Paul G]

I tried doing a compression test. The headers are in the way of getting my compression test gauge fitting in the spark plug hole. Only diagnostic tool I can see right now is a steady needle on the vacuum gauge, and vacuum at 16". Every electric fuel pump I have used has put me on the side of the road. None of them high dollar pumps. Now I can put a Carter mechanical on and be confident that it will work.

If there is more happening in this engine I will find it, eventually. I have a few engine options. The 505 is going back together, slowly. This junk is taking all my time and $$ right now. When the 505 is done I might put it in this car, then go through the 383, it can go in the 72. Low deck is a better fit under the factory flat hood. 

[BSB67]

I'm not questioning what you're doing at all.  I'd do the exact same thing.  Just slowly whittle away at what is not right.  Actually sounds like fun.  And I'm sure you'll get to the bottom of what ever ails it.

Does your gauge have a flexible hose?  Even if you get a couple of cylinders, it will tell you a little something.

[firefighter3931]

The HMV278 is a nice street cam that works great. A buddy installed one in his 426ci street wedge which was using the factory 64 log ex manifolds and very restrictive 64 4bbl cast iron intake. This is a restoration type build and everything has to look right. The factory '64 intake and exhaust manifolds are power killers. With the Crane cam it made descent power ; 352hp/465tq handicapped as it was. Pretty sure it would have picked up 40-50 hp/tq with a better intake manifold and a set of long tube headers.

The DP4B & CH4B are excellent manifolds and far superior to the oem intake manifolds. Not quite on par with a performer RPM but not really that far off either. I would definitely buy that one locally and use it....along with the PF750DP'er

Check for shaft slop in your distributor. Over time the bushing will wear and create clearance which can cause the spark bounce/scatter that you're describing.



Ron

[BSB67]

Here is a picture that says a lot about the difference between the factory hp intake and the DP4B.  Similar in configuration but different in height, runner cross sectional area, and volume.

[Nacho-RT74]

Even the basic Edelbrock Performer ( not the RPM ) is higher than the factory iron intake by about the same than the pic posted with the DP4B, with the advantage is ready for the spread and the stock choke coil assembly for 73

The DP4B intake gets the coil on diff location than stock, so the stock rear compressor brace won't fit. Believe or not that's the reason I decided to go with the Performer ( having a DP4B somehow handy ), aside the spreadbore setup and stock mounting coil.

Still with that, I had to trim a bit one of the coil brackets provisions to be able to fit the compressor rear bracket to this provision. That's how I advertised the diff height with the stock iron compressor ( around half of an inch or a bit more )

Also had to trim a front reinforcement on the Performance intake to fit the front rail compressor bracket. He DP4B seems to be in the same deal on this.

Just posting those notes to take in mind depending on what you want to build. Not saying one is better than the other, but I know you are pointing out to get the A/C system back in... dunno if stock or not.